Radiorheostat



`30 with such other Patented May 5, 1925.

AUGUSTINE E. GREENE, OF WILLIMNTIC, CONNECTICUT.

RADIO RHEOSTAT.

Application tiled December 15, 1923. Serial No, 680,977.

To all whom it may concer/n:

.be it known that I, ArorsriNi: E. GREENE, a citizen of the United States of America, and a resident of Vl/'illimantic, in the county 4i of Windham and State of Connecticut, have invented a new and useful Radiorheostat, of which the following is a specification.

My invention rela-tes to rheostats especially designed for use in the radio art, and consists in general of a main resistance elo ment, a bracket for such element, said' bracket being provided with terminals, a hollow, externally screw-threaded member upon which said bracket is mounted and by l5 means of which the saine is held in place, a second bracket supported. with said element from the lirst, said seoond bracket being provided with a Vernier brush and Stop, a

hollow shaft carrying a contact arm for said element, said shaft being journaled iii said hollow member, an operating member or knob'for said shaft, a shaft or spindle r'otatably arranged in said hollow shaft, a

Vernier secured to said spindle in contactual relationship with the brush carried by said second bracket, said Vernier having a stop member to cooperate with the stop carried by said second bracket, and an operating member or knob for said spindle, together arts and members as may necessary or esirable in order to render the rheostat complete and serviceable in every respect, all as hereinafter set forth.

One objectof my invention is to produce a comparatively simple yet highly eicient radio rheostat, wherein a single nut or screw is employed for supporting all of the other parts and members in and from a panel, which screw affords convenient and safe 4o means for securing and holding said parts and members in place.

Another object is to provide a radio rheo stat with a vel-nier, whereby it is possible to obtain very fine adjustment of amounts i5 of resistance beyond anything that can be obtained with or through the main resistance element alone, or, in other words, to regulate the resistance with great nicety or exactness.

A further object is to construct a rheostat in such a manner that the parts and meinbers theerof can be readily assembled.

Other objects and advantages will appear in the course of the following description.

I attain the objects and secure the advantages of my invention by the means illustrated in the accompanying drawings, in

which-- Figure is a rear elevation ot' a radio rheostat which embodies a practical forni of my invention, portions of the Vernier being broken away to disclose the construe tion thereof, and, Fig. Q, a section through said rhcostat, taken on lines 2N2, looking in the direction of the associated arrow, in Fig. 1.

In the dravvings a fragmentary portion of a Support or panel, such as is commonly used in the construction of radio is represented at l. The panel 1 has an oper.- ing 3 bored through the same. A horizontal nut or screw 4 is provided to tit Within the opening 3.

The supporting screw 4 is externally screw-threaded, has a head in which are screw-driver slots (i-JS, and is hollow. The screw 4 is inserted in the opening 3 from the front side of the panel 1 and thi` head 5 bears against said side. A. hollow shaft 7 passes through the screw 4 and is adapted to be rotated therein. A large knob 8, having a dial 9 and rovided with a bushing 10, is mounted in tliont of the head 5 on the forward terminal of the shaft 7, a set-screw 11 being employed to secure said bushing to Said shaft. The screw 11 is received in a radial opening 12 in the knob 8, and said screw is tapped into the bushing l0 and bears at its inner end on the shaft If'b Gener ally, the knob 8 with its dial, and a knob 13 presently to be described, are of usual and Well-known construction.

Secured to the rear terminal of the hollow shaft 7 is a resilient Contact arm 14. The arm 14 at its free end contacts with a main resistance element consisting of a strip oi insulating material in the form of a ring, band, or annulus 15, and a wire coil 16 on said annulus. This resistance cleineiilt is 'supported by and from a bracket 17.

The bracket 17 may be stamped out of sheet-metal, and has a hub 18 below and a flange 19 above,` said hub being internally screw-threaded to receive the screw 4. Both the hub 18 and the flange l!) extend rearwardly from the vertical part of the bracket 17, and said flange is arcuate in its lengthwise direction to receive the upper portion i?, "e, nt li iffion is atn'een the. anti is tho untlorsitle Liang" :intl hand hoing hantt il is Secured to thtx atta nl' tufo Hows 2O` two tml [wir .t washers 2;). pas 1;;fu1rtll through tlm ho Hao@ fl to receive. the i :il ahorn said flange*v "fzl lt' is attatlnetl to ht-twovn thtJ hantl l htinvon saitlbantl an.; tl non The other toitunai -rf t, toil lt) is attzfu'hotl at 24 to thl fmia' ,t [tn angular., vornier Stop t. 125': if: vt-unal to tho flange fit th Snow 2t. Saitl horizontal part thaty is trawl t3 antl tho htatl it) with their ola tho rhoostat tot tho wires .al to the soutif@ tu? hanfl til' Hl, 2li latter terminal a tlownwartl itl tart-named vxwip, @op (Algo of tho i rouztuaotl to form tw-th honig rtailit'nt in- .iltl ot' n'hit'h tho lirat'ltot,

Et;-`illtl;t'. ot fpinflle )f oxtoncls eo lp; rotatotl in tht :la him?, t is accurati .mittal ol' Saul spindle. on. ttt' tontatt with tho t'noh S4 The kuoh l ont of tht` haoh 8. whioh iameotlatol-v in front ot' i l. www t. Yornivr col* hat., "Lu animar/.l on tht` roar tol'mit tlirwtiv lwhiml the fr at itittl to aitl spinon iii. im: ti.

terminals of the a iro 323 on tho poriphory of the (list: 3;), am'l tho tontavingf ond of the brush Q5 aro such that l-iaitl dixo. when ro tated in wither tlirwtion. is stoppttl htnforo that portion of :saitl ptfriphory whirl; i lahtween Saitl ttzminaiy arri\t-v at ah and of said brush` vosmttion of rotation lining pro1 tlncetl hy saitl pin n'hou it om'onnters tho odge of saitl stop that in tht` imtmzdiate path ot' the pin.

'hen tho parts artasreemhletl. the @w 4, which supports the hracktrft, l?, t'otatttl to draw saitl brac-kot; tightly against the hack side ot' the `panel l, thus not only Stipporting but Securing Said hratkot in place.

The hollow shaft T i5 hohl` against appreciable entlwists movement h v thtI bushlng lt) and the tlial E) which naar against. ththead 5 of tho Sore-w at ono and, and lo; tho resilient arm ll which heats 'at its tra@ terminal againht tht: rear otlg'o oi the, main resistance element or ot' thc coil It) of Such member, at tht*y other ontl. The apintlhI 2t) is hohl against emlwiso movement, hy tho knob lll which hoax-s against tho knob n, at on@ and. and tht Ytzrnitr huh 3U whifh heara against the hollow `ahat't T. at tho othor @ntli Forming tho t-iiwnit between tho hint/lingposta (L20-w20) aro tho hrat'ltot t?. tht` .-ll'on' Jr. the` hollow `shalt T. the arm il. anti tht, t'osistam'o t-oil It. also tho hrm-kot tht hrush 25. tho rornior r0 i taxwtl wire of. and tht` huh 130. aml tho spindle '19. togothtr with saitl hollow shaft. saitl arm. and said coil.

By turningA tho knoh o' the Contact atm lt is movotl. through thtVA motlinm ot' thtA lwslr ing 1t) antl tht` hollow Ahatt T, to tlitoront positionr-l on tho main resirltanto ult-montr` autl tol'respomliugly tlitl'orent amounts ot' to aistame aro thorohy protlut'vtl in tho rirt'uit hotn'ttn the himling-posts. in tho manM infr woll nndolstootl h v those slgillotl in tho art. Ami hy turnin; r tlu knol I? theA tornio:- is rotatotl to protnt tho wirt* i525 at tlit'lorout points to tho liras-h 2H. antl act-ortlingl-v thier gfraflationaI ot amounts` of rosistant-t aro protlut'otl in said wirvuit. auch resistance being int'roasotl a tho tw'minal IH ot' yaid Wire approm-hw` thtx hrurrh 12h. aml dotrtawtl as thv longth 1%.', ot' -titl wir@ ai'iproathts sai-'l luuSh. Motion is impartial to the vomito (liso 32 aml its rvaistantt wiro, when tho ltnoh 13 is rotated. through the motlium of tht' spintllt .29 and tho hah ."tt. .Mr provionsly observed. thtx Stop QT and the pin 3G limit the` rotation in tithor tlitot'tion of tht1 tlist- 2li. and prevent the brush 2R from he coming: (tiwwigg'agna from tho niro .'fL or` in othor wot-tls. prow-nt that part of tho tt-- riphory ot' taaitl ist whit-li if hnta'ton the torminal 34 :tml theA lonpgth 32? at' Q l wiro `from passing lonoath tho fr@ or honing terminal-ot said bmah.

ln practivtf. the arm t4 is t'irfff wt to throw lit.)

in approximately the desired amount of resistance, and then the Vernier is set to increase or decrease said resistance in some slight degree; or said vernier may be set at a point which produces tin2 desired result even when the ":osiliiilm of said trui subsequently changed.

More or less change in the shape, size, construction, and arrangement of some or all of the parts of this rheostat may be made without departing from the spirit ot my inv vention or exceeding the scope of 'what is claimed.

lVhat I claim is my invention, and desire to secure by Letters Patent, is-w 1. The combination, in a rheostat, with a hollow threaded member having a head, of a bracket having a hub tapped to receive said member, and also having a flange, a, main resistance clement and a Vernier brush and stop bracket secured to said flange, a hollow shaft in said first-named men'ibcr, a Contact arm secured to said shaft Yfor said element, a spindle in said shaft, a collar secured to .said spindle, a Vernier disc of insu-- latin r material seznred to said collar, said disc being provided with a stop pin, and a vcrnier wire carried by said disc, one end of said Wire being in circuit-forming relaV tion with said collar, and they other end being remote troni tbc t.'

2. The comiiination. in a rheostat, withV a main resistance element. supper-'ting means for said element. said support being pr vided with bindingxosts, a Contact arm for said element, and means to operate said arm, of a spindle, a vcrnier disc of insulating material mounted on said spindle and provided with a stop pina Vernier wire carried by said disc, one end of said wire being electrically connected with said spindie, and the other end being remote from the first, a brush for said `ivire, said brush being electrically connected with one of said bindingqmsts. and a stop in the path of said pin to prevent said wire from being actuated out of contact with said, brush.

3. The combination, in a rheostat. with a hollow threaded member haring a head to contact with one side of a panel in which such member may be inserted, of a bracket having a hub which is tapped to receive said member, and also having a flange, said bracket being adapted to contact with the other side of such panel. and with said head secure said member and the other parts of the rheoslat to thc panel, binding-post members carried by said bracket, a main resistance element and a Vernier brush and v .stop bracket secured to said flange by said bindingqiost members a hollow lihat't in said lirstxiariied member, contain. am; secured to said shaft. for said clemenff. said shaft. a feo zo y a vernici disc relation with to said collar, said disk being provided with a stop pin, and a Vernier wire carried by said disc, one end of said wire being in circuit-forming' relation with said collar, and the other end being remote from the first.

fr. The combination, in a rheostat, with a hollow threaded member havingr a head, of a bracket having a hub which is tapped to receive said member, and also having a flange, binding-post members carried by said bracket, a main resistance element and a Vernier brush and stop bracket secured to said flange by said binding-post members, a hollow shaft in said first-named member, a contact arm for said element secured to said shaft, a spindle in Said shaft, a collar Secured to said spindle, a Vernier disc of insulating material secured to said collar, said disc being provided with \a stop pin, a. Vernier wire carried by said disc, with one end in circuit-forming relation with said collar, and the other end remote from the first. Vernier brush bearing on said v wire, and said pin being so located that said wire is prevented thereby and by said stop bracket from passing out of contact with said brush.

5. The combination, in a rheostat, with a hollow externally threaded member having a head, of a. bracket having a hub tapped to receive said member, and also having a flange, a main resistance element comprising' a band of insulating material and a coil, a second bracket, screws and nuts by means of which said band and said second bracket are secured to said flange, and with one of which screws coil is connected, a hollow shaft in said member, a contact arm carried by said shaft for said resistance element, a spindle in said shaft, a collar secured to said spindle, a Vernier disc of insulatingr material `secured to said collar. a Vernier wire carried by said disc and having one end in circuit-forming said collar and the other end at a point remote from the lirst, and a brush extending from said second bracket to bear on said wire.

(i, The combination, in a rheostat, with a hollow externally threaded member havin a head. of a bracket having ay hub tapped to receive said member. and also having' a flange, a main resistance element comprisingr a band of insulatingir material and a coil, :i second,bracket, screws and nuts by means of which said band and said second bracket are secured to said flange, and with one of which screws one terminal of said coil is connected, a hollow shaft in said member, a contact arm carried by said shaft for said resistance element, a spindle in said shaft, a collar secured to said spindle, a vernici disc of insulatingniaterial scoured to said collar, and provided with a pin, a Vernier wire carried by said disc and han one terminal of .said

lll)

:md thil @ihm nu Hfst, and a f 0nd bracket i.; be amp Supported by mid path of said pn i@ limit thv, mm' sari disf: fm buik uouifm? maid pm 

